# Why do mineral ore deposits occur?

**URL:** <https://boards.straightdope.com/t/why-do-mineral-ore-deposits-occur/338014>\
**Category:** Factual Questions\
**Created:** [January 2, 2006, 12:21am UTC](https://boards.straightdope.com/t/why-do-mineral-ore-deposits-occur/338014 "2006-01-02T00:21:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\
**Post date:** [January 2, 2006, 12:21am UTC](https://boards.straightdope.com/t/why-do-mineral-ore-deposits-occur/338014/1 "2006-01-02T00:21:10Z")

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The origin of stuff like limestone, coal, and organic phosphate deposits is pretty clear, but why do we find concentrations of ores like iron ore, copper, aluminium, gold, uranium, etc? They’ve been there since the origin of the Earth, so what caused them to coalesce? Why are they there and not just mixed in the the crust?

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**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\
**Post date:** [January 2, 2006, 12:49am UTC](https://boards.straightdope.com/t/why-do-mineral-ore-deposits-occur/338014/2 "2006-01-02T00:49:26Z")

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WAG

they solidify at a certain temp, so when a section is cooling that is what comes out of the liquid